Immobilizing enoxacin on implant by polyvinyl butyral coating to promote osseointegration in osteoporosis with infection

Abstract

Controlling infections and inhibiting osteoclasts are crucial for the prognosis of bone abnormalities by implants in osteoporosis patients. Here, using bio-inert polyetheretherketone (PEEK) as the representative and polyvinyl butyral (PVB) as a coating medium, a repeated soaking-drying method was developed to decorate PEEK with porous treatment (SPEEK) in PVB solution containing enoxacin (ENX). PVB and ENX were painted on SPEEK to form SPEEK/PVB-ENX*3 according to the controlled preparation strategy. SPEEK/PVB-ENX*3 exhibited porous morphology with immobilized ENX, hydrophilicity, and kept mechanical properties. SPEEK/PVB-ENX*3 showed antibacterial activity of successive 6 days and cytocompatibility. Moreover, SPEEK/PVB-ENX*3 maintained antibacterial stability and cell activity for 4 months. SPEEK/PVB-ENX*3 inhibited osteoclasts but promoted osteogenesis in mineralization. The in vivo drug monitoring of implanted SPEEK/PVB-ENX*3 showed that ENX could be fully released and metabolized in 7 days, eliminating antimicrobial resistance (AMR) caused by residual antibiotics. The in vivo experiments of micro-CT, immunohistochemistry, and histological staining at 6 weeks after surgery on osteoporotic rats showed that SPEEK/PVB-ENX*3 had antibacterial activity, inhibition of osteoclast, promoted osteogenesis and safety. This study develops an effective method for the biofabrication of implants needed for the clinical treatment of osteoporosis from clinical considerations.